Sensory apparatus: Features

Sensory apparatus
We will discuss:
Receptors
The view
The ear and vestibular apparatus
The taste and smell

This system allows adjustment of internal relations of living organisms to variable environmental conditions in which they live. Notice the changes in the environment and transmits the information to the bodies which carry out the regulation of body functions through specialized cells called receptors. In most cases recipients are cells or groups of highly specialized cells called sensory organ (eye, ear, etc.)..

Receptors
They are classified into exteroceptors, located in the skin and organs projected outwards (eye, ear, nose, mouth); proprioceptors found in the somatic muscles, tendons and joints and visceroceptores located inside the body . Stimulation of a receptor may cause a sensation conscious or merely amends organic activity, automatically and without which the individual perceives it. Among the skin sensations are received by receivers or Meissner corpuscles (touch), Pacini (pressure), Krause (cold), Ruffini (heat) and free nerve endings of pain.

The view
The light-sensitive receptors are part of a complex organ-the eye. The eye acts like a camera. Among some of its parts are: the sclera, which in turn becomes the anterior cornea, the choroid, the retina, the pupil, iris, lens, located about 2 mm. behind the cornea. The space behind the lens is held by all, the vitreous body. The front of the eyeball is protected by a mucous membrane called the conjunctiva. In the retina there are two kinds of receptors: rods and cones. The first lighting appreciate quantitative differences, the second color tones. It is in the retina where it forms the sharp image of a distant object. When the object is closer to the visual features of an automatic adjustment by which the lens becomes more convex and increases its refractive power (accommodation). It is also the phenomenon of convergence automatic, so that the eyes are oriented toward the object being viewed so that their images fall in equivalent of both retinas. The man can distinguish about 130 shades of color.

The ear and vestibular apparatus
The vibrational energy that our analyzers sensory brain interprets as sound is one that extends from 20 to 18,000 cycles per second. These vibrations stimulate certain cells in the ear conch. The ear has three parts: outer ear, the canopy or ear to the eardrum, middle ear bone cavity with four holes, and inner ear, which consists of various structures related, but distinct functions. It is in the ear where the spiral organ of Corti that are the cells that are stimulated by the vibratory movements of the basilar membrane and triggers the release of nerve impulses to neurons. Furthermore, the vestibular apparatus, as well as providing the notion of position sensory triggers automatic mechanisms that tend to maintain balance. This consists of the semicircular canals, utricle and saccule.

The taste and smell

Both are one and the other chemical senses. Just as taste receptors are stimulated by chemicals dissolved in saliva and in intimate contact with them, so the smell can detect volatile substances. Receptors in taste buds are neuroepithelial cells that are in contact with sensory nerve fibers of certain cranial nerves. The primary flavors are: salty, sour, sweet and bitter. The salty and sweet are seen more strongly at the tip of the tongue, acid in the side edges and bitter in the back. As for the smell receptors are much more sensitive than taste and have a great capacity for adaptation, because once the individual informed of the presence of an odor, the feeling was quickly extinguished. The smell receptors are located in a small area of the mucous trap, in the superior turbinate, attached to the ethmoid bone.

Related Topics
* Urinary
* Locomotor
* Respiratory
* Circulatory System
* Nervous System
* Gastrointestinal

*Automatic Translation